Telephone system



TELEPHONE SYSTEM F iled March 18, 1926 14 Sheets-Shet l M Ma" /f. Mam);

Nov. 8, 1927.

1,648,053 G. R. MARTIN TELEPHONE SYSTEM Filed arch 18, 1926 14 Sheets-Shqefi 2 Nov. 8, 1927. 1,648,053

TELEPHONE SYSTEM Filed March 18, 1926 14 Sheets-Sheet 3 Nov. 8, 1927. v 1,648,053

G. R. MARTIN TELEPHONE SYS TEM Filed March 18, 1926 14 Sheets-Sheet 4 Wye/71m Gear e Mar/777. fly mm Nov; 8, 1927. 1,648,053

G. R. MARTIN TELEPHONE SYSTEM Filed March 1926 14 Shee Noi. 8, 1927.

G. R. MARTIN TELEPHONE SYSTEM Filed March 1926 14 Shee //7|/e/7/0/1' Georye f2 Mar/m.

Nov. 8, 1927. L648,053

G. R. MARTIN TELEPHONE SYSTEM 7 Filed March 1926 1.4 Sheets-Sheet 7 G. R. MARTIN TELEFHONE SYSTEM Nov. 8, 1927. 1,648,053

Filed March 18, 1926 14 $heets-$heet 8 Nov. 8, 1927 mamas G. R. MARTEN TELEPHONE SYSTEM Filed March 18, 1926 14 Sheets-Sheet 9 14 Sheets-Sheet //7ve27 /;?//1' f r e a/ //1. fly j fl G. R. MARTiN TELEPHONE SYSTEM Flled March 8 1926 Nov. 8, 1927.

Nov. 8, 1927" 1,648,053

G. R. MARTIN TELEPHONE SYSTEM Filed March 18, 1926 14 Sheets-Sheet Wye/72w Gearge Mar/m.

Af/y.

Nov. 8,' 1927.

1,648,053 G. R. MARTIN TELEPHONE SYSTEM Filed March 1 1926 1.4 Shee Nov. 8, 1927.

1,648,053 G. R. MARTIN TELEPHONE SYSTEM Filed March 1926 14 Sheets-Sheet l3.

Nov. 8, .1927. 1,648,053

G. R. MARTIN TELEPHONE SYSTEM 7 Filed March 1926 1 l4 Sheets-Sheet 14 //7 l//7/9/".' George Mar/m.

Patented Nov. 8, l927.

GEORGE MARTIN, OF EAST GRAill'G-E, H11? iiiiSlZGrll-IGR TO WESTERN ELEG- TRIC COTVEPANY, IlZ-ICOREQRATED, 01E" IJE'W" YORK, N. Y., A COEI QIt-ATIGN' (5F NEW? YORK.

TELEPHONE SYSTEM.

This invention relates to telephone exchange and more particularly to systems employing automatic apparatus for establishing connections.

The invention is in the nature of l111- movement on the system shown in Patent No. 1,573,412., issued W. hiacljougall and A... S. Bertels Feb. 16, 1.926 and it is the object DYE the present invention to provide an improved. testing system of the type disclosed in th at application tor lector switch units.

i A "feature of the invention is the provision oi means for indicating the identity of the selector under test.

A further feature oi. the invention lies in the provision of means for periodically checking the accuracy 01 the above mentioned identiying; means.

An additional feature of the invention lies in the provision of improved means for synchronizing a plurality oi? switches.

A still "further feature of the invention lies in the provision of means for the nonsequential use of testing selectors.

To give an idea of the appearance of tnese features in the ope 'ation of the present embodiment of the invention a brief outline ot' the operation will be presented. A routine test is started with all the apparatus at rest. The operation of the start key advances a pair of directing selectors one step. These selectors are synchronized by a special arrangement and control the remainder ,of the test circuit. One of a number of sequence switch type selectors or connectors is then positioned, to associate the test circuit with the district selector or the otlice selector which is used as a test selector. 'lhcso connectors are so arranged that the test selectors may be used in any order. It the test selector is busy the test circuit waits until it becomes idle at which time it is made busy to service connections. At this time a register or locating selector is positioned. under the control of the directing selector to determine the first incoming selector to he tested. The testselector is now directed. without advancing its associated sequence switch oil-normal, to the first in- CODllllQ' selector in the group where the test is to be started. The incoming; selector is then operated to select one o't a group of final selectors having access to the final multiple test line and the selected final selecf 5 tor is positioned on that test line. The control relays oi the incoming; selector are tested by the test c rcuit af :2 which the final multiple test line tests the ringing opera tion. The test circuit and the test linh cooperate to test the supervisory relay of the incoming selector after which the incoming; selector is released. The test selector and the locating selector are each advanced one step and the tests are repeated on the next incoming selector. The incoming selector. are separated into groups by means of overflow lines and circuits are completed with hot. the locating selector and the test selector in the overflow position which cooperate to advance these selectors to the ext incomin selector. Lamps are also provided under the control. of the locating selector and a kev which identify the incoming selector under test. Any number of. selectors may be 75 grouped together for the purpose of the test. When the test of such a group is completed. the test selector is returned to normal and the directing selectors advanced one step. In this position the connector switches. and locating; selector are reset to test thenext group. To begin a test at a particular incoming selector groups of keys are provided which arbitrarily position the directing selectors and the locating selector in posi tion. to test the desired incoming selector. Other keys control the setting 01 an incomselector in a position other than that lcadii k to the final multiple test line.

Referring; to the accompanying drawings, Fig. 1 shows a district selector used as a test selector. Calling subscribers lines are normally extended to the district selector by means ot the line finder shown therein and the operation of the switch is normally directed by sequence switch 100. When used as a test selector, it is directly connected to the testing controlling circuit at the contacts of the connector switches of the test apparatus and the selector is c tr lled. from we 1,648,053 i-i] nect the incoming selector switch to a test line located on the final trains.

F shows test line used alone for testing certain functions of the incoming selector switch and in conjunction with the test apparatus ior testing other functions of said. switch.

5 slows keys to control the selection ol :1 icular incoming selector lest together with a. soy for relui ihe test circuit to normal.

0 shows 6 ector switches 600 and (350. l'hcse connectors the sequence switch type and are controlled in such a mentor that particular selector switches are u from service and associated with ting control cir uit in a non-sequen- 7 illustrates apparatus and circuits to control the positioning of the test selector. Figs. 8 and 11 1 lie a cup of selec ors acne? in the icse d reruns selec- L'cl'lCS 800 and nature of rcgiste i tors operated in pairs, S'Vl 1100 operating together and switches 810 and 1110 coope z mg with each other. lhe terminals served by each hrus-h are connected to a terminal rack which is crt r nected to other teriiinal strios and ll once to the desired. appa'atiiis. o

l are shown on made to the al Dougall and B ment of similr l 11' c" .wconnection.. 9 shows a prir of locating which control the se ection oi the j switches to he tested and in coopera ioi the lamps indicate the selector under lie" Fig. 10 illustrates apparatus and circuit for cor t olling the incoiniiiig selector switch to he tested. This control circuit designer to direct the incoming; selector switch to a iinal select 1 switch whi th is in turn directed to a linal nu. lo test line.

Fig. 12 illustrates 2. compound liiui 1 \ice operated in such a manner that ch 1210 progressively positioned to count a predetermined. period of time "tor the testing control circuit to seize and test a selecttr switch and stzrt the test of an incoming: selector switch. Switch 1200 is operated to time the period during wiich the i900 hing selector switch is under te The time period allotted for the operation o switches 1200 and 1210 is adjusted so that should the various operations not he completed withgm l. l.

in such period, an alarm is sounded to indicate the fact to an attendant.

l ig-s. 13-3 and ll show auxiliary apparatus for zssisting in the testing oi the incoming; selector.

15 is a diagram showing the order in which the sheets oi. the drawing should he ar anged.

Key 601 of Fig. 6 is a start key; the operation of key 558 returns the test apparatus completely to normal; keys 500 and 501. together with key set-s 510 520 and 530, control selection of a particular selector for test; lteys 1302 and 13 1;, together with key sets 1050 and 1000. cortrol special tests, key 1039 is o] ie .'ated to repeat a test on an 'i o ad key 1038 to ad 11 a 'l'ch when trouble is y s well as keys 500 .101 of V veetrically released connection has been mace d1 the parrr urm .i K t 1 v they set we is released h the operation oi? the retuin to normal key. The tlllOCtiDil' selectors of Fig 8 and 11 the locating selectors ol? ar the tiniinc switches of 2. 12 are all switches of the step-hy-step in order that the two switches cons muting the directingsolector shall. he in synchronisin. special means ha. hcen provided for the switches from normal from ter 1 and so for moving; them rapidly to a 7 )articular terminal. Briefly the operation as loll 4' The operz'it uq circuits for the uiaz 'i'icts oi the s id throue h tho haul: of the switch. A sec nd circuit is provided For he act of the I switch through a relay. relay is p1 evented from operating); liy

ircuit ti 1 the terminal hank. 1 cross-counected to around through. relay Tai and all terminals are the 'lCl'llllOil pac terminals or in 1am:

i her cure in pa.

ins O Particuh c the oi' erzu tion oi. ltey 556, 110 operating circuit is maintained until the desired terminal 800 and 1100 ting selector and switches 810 and 1110 make up the s cond directing selector. mahy directing selectors tog'ether with the relays associated therewith may he provided as are necessary.

responding brushes of all directing selectors are cross-connected to the'saine racks. Therefore, in order to simplify the drawings the corresponding switches of the directing selectors have been grouped together and for the same reason separate terminal.racks h ave been shown with the contacts thereof multipled together. The first are of each switch is used for positioning the switch itself. Arcs S02 and 812 in cooperation with the 10- cating selectors mark the last incoming selector in the group for the purpose of resetting the directing selector. Arcs 803 and 813. 805 and 815, 806 and 816 control the amount of resistance used in the fundamental circuit at various times. Arcs 80-1: and 81d vary the capacity between the fundamental circuit and ground. Key 809 may be used to remove this capacity. Arcs 1103v and 1113 control the positioning of the locating selectors of Fig. 9. Arcs 1104: and 111 1- are cross-connected to operate relay 1225 or relay 1443 when necessary. Relay 1225 transfers the fundamental circuit from relay 122% to relay 1228 for incoming selectors employing 24 volt transmission. Relay 141- 13 is used to alter the test when a three wire incoming selector being tested. Arcs 1105 and 111.5 are cross-connected to alt r the operation where the district selector switch is reached tl'irough a line switch and where the final multiple test line does not supply the synchronizing pulses as described later. Arcs 1106 and 1116 control the selection of the district selector which is to be used as a test selector. As will be pointed out in greater detail later, the wiring of the sequence switch type connector switches permits the use of the test selectors in any order under the control. of these arcs of the directing selectors. This renders changes in the test circuit to care for changes in the grouping of the incoming selectors much easier than in the arrangement of the above identified Mac- Dougall-Bertels patent.

The locating selectors have a plurality of functions. They serve to control district group selection; they serve to indicate the number of incoming selectors in the panel bank; they also cooperate with the test selector to insure that the indication is correct. The locating selectors are positioned under the control of the directing selector to correspond with the number of the first incoming selector in the group to be tested. The are served by brush 903 of the tens locating selector completes the counting relay circuits for determining the group of incoming selectors to be tested.

The incoming selector is identified by the f 31116 in which its terminals appear, by the brush which has access to said terminals and by its individualposition among the 100 terminals to which each brush has'access. Each district selector brush serves .100 sets F51 mi:

of terminals which are divided into 8 groups of ten sets each and two groups of five sets, each group being followed by a set called an overflow set. The first set of the groups will bear the following numbers; 0, 1.1, 22, 33, 414-, 66, 77, 88 and 94.. The overflow torn'iinals will bear thenun'ibers; 10, 21, 32, 43, 5%, 65, 76, 87, and 99. The locating selectors are positioned by grounding corresponding terminals of brushes 906 and 916 through the directing selector. The group beginning with No. 9% is arrived at by rro-unding the No. 9 terminal in the tens locating selector and after that switch has been brought to rest transmitting the ground to the No. 4 terminal in the units locating selector. The units locating selector is ad ranced one terminal each time that the district selector is advanced one terminal. It is advanced automatically over and 22 terminals in order to retain the decimal relation between the switches, and at the same time the tens locating is ac vanccd one terminal. At the over'iowxpositions circuits are closed through brushes 902 and 912 which cooperate with a circuit con trolled by the overflow position of the district selector to advance the test. The failure of the locating selectors and the district selector to reach overflow position at the same time blocks the progress or" the test. Brushes 901 and 911 operate certain relays to indicate that the test of the group has been completed.

If an incoming selector failsto operate correctly and its identity is desired in order to make adjustments therein, lrey .956 will be operated. This key supplies battery to lamp set 940 and thence throughv a contact closed by the connector sequence switch to ground identifying the district selector being used as a test selector, and therefore, the frame on which the incoming selector appears. It also operates relays 951 and 957 to transfer the lead which has been used in brush selection to one of the set of lamps 960 identifying the brush of the district selector. In addition it will supply battery for indicatingthe number of the incoming selector.

The operation of the timing arrangement of Fig. 12 w ll be clear from the detailed description to be given later.

General description.

An automatic routine test of incoming selector switches is started by the actuation of key 601. The operation of this key brings about the movement of the first directing selector to its first position. With the directing selector positioned ground is connected to one of the contacts cross-connected to brush 1106 to position one of the connector sequence switches in position to test the district selector which is to be used as a test its Nos. 11

. hack contact of relay selector. This selector is then tested for busy condition and is seined for use. ll hen ready for use, sequence switch 700 is advanced and the locating selectors are positi uied. District brush and group selections made. leaving the test selector on the terminal), leading to the first incoming selector or the group. This selector is tested for busy condition and when it becomes idle is con trolled to select one of a group oi final selectors. This itinal selector is then positioned on the final n'iultiple test line. The test line applies ccr'ain to after which the test apparatus and the test line cooperate to test the supeiwisory relay of the incoming selector. The incon'iing se ector is then restored to normal as well a the final selector. The units locatin selectors and the test soector are then advanced 1 second incoinii sele 1e group ot selectors to he to t tion the (lllCillu"' between overflow li here n one poeater n. we

a group is reached, the is restored to normal and ector reset or other selectors posiether with the locating selectors,

t iithe new group.

4- i, 1 L Kit Detailed description.

in order to start routine test of all thincon'ung selectors in an oti'ice, s t key wil be operate The oper key tar a. ation of closes circuit for relav T01 nrovided a the connector sec 'uence switches, such and {350. are normal, whicl'i circui' traced from of relay (01, lower left upper contact of earn t start key (501 to ground. I for relay T01 is cl d hetore this k in o; iit is opened and maintained as long as any one cit the connector sequence switches is oil-norm and hey (501 is operated. l his circuit extends from the winding oi relay T01 over the lower right contact of ca (502, or over the lower left contact of c. 602 and the lower right contact. o'l. cam 61' cents osc at contact 613 of key 601.

The operation oi relay '1 01 closes a circuit for advancing; the .tirstpair of directing selectors 800 and 1100 to their first oil-normal termina This is acco relished by means ot a circuit from ground over the outer litcontact of re 13* 701 nductor 708 light 1 n 550, serially through the normal terminal This circuit is extender through brush 801, he l: Contact and winding of steeping magnet to h 1 switch 800 to its ttery, stepping first oft-normal posit-ion ans opening the circuit of magnet 80 The operation of relay '7 O1 closes a second circrit from battery through the winding of stepping; magnet 80? and its heel; contact, through the winding of relay 850. right melt contact of relay 1150, right hack contact of 1' slay i151. conductor 11 i, lower contacts of cani i to around at the inner right contact of m Z (ll. is

s smi 'n normal po- :ch 800 remains 1 winding relav O is shunted I und connected to the In 'uial tero l'll$l1 801. -l1CG of switch i 'oir opens this peration oi: relay 850.

coi'npletes a cir- *er its front contact magnet act x; directing l. terminals. hacl: conover 1;; and concor-tact conduc- '1 T02 which locks cc and cor-tact key 601. a" locking circlosed from conductor ll'i'tl, 'lront conductor 75- 1 to "a ot relay 11o lhis lay T01 operated .sto l over condr.

lis "e rec, until the s nei ce we returned to 1th all connector sequence rn'inzl the circuit of relay T01 is opened and that relay releases, opcuiinethe locking; circuit ot rela 1152} and relehsiuc the latter relay. n

n closes a circuit 0 winding of relay 11:" 1153 in operati r ue'h ili 733, to ground at the enter i of relay 1153. The operaronnec J from the relay igh trout relay 5H. con; tor 55%, lower ,'.ontacts (it can] 703 conductor 70?). to hrush 1 0 of directing" selector 1100. The tern'ii of brush G II'O connected to a. crossy are cro to another cross-connecting lJlOt'lI. terminals on this second connecting control the positioning oil the conn sequence switches 600 and 650. i sthe cross-connections to he as iown.

1e circui'u may he turther traced exec conductor 1157, upper right contact run r" 1 053 winding of sequence switch magnet 650 to battery. Sequence switch 650 is moved from position 1 to position 2 in this circuit. It is then moved from position to @051 .ion 1 in a circuit lroi'n battery t irough the Wind ing of the so re rnet, upper left contact or in 653, loner 1'1 he cents" of earn 605, upper right contact 01' cam to ground. ln position of connector quence switch 650 the d" is to be employed as a. test s il ctor is tested to .lind Whether or not it is busy.

The district selectors which may be used as test selectors are 01 three types. One type is that adapted to be selected by means of a line switch individual to the calling line. A district selector of this type may be found in U. S. Patent 1,895,977 to ll. A. Stearn et al., "ranted l lovembcr 1, 1021. A second type of district selector is directly associated with the line finder and sender selector. A district selector of this type may be found in U. S. Patent No. 1,541,856 to F. S. Irvine, granted June 9, 192 5. A third type of district selector is controlled by a link circuit and is also directly associated with a line tinder. A district selector of t is t pe is disclosed in U. S. Patent No. 1,567,072 granted to VJ. 1" 'es, December 20, 1925. The district selector which has been. shown in full and associated. with the first operative position of sequence switch 600 is oil the link type. A selector of this type norn'ially stands with its seoi'ience switch in position 2 and is associated with a link circuit prepared to serve an incoming call.

Viith sequence switch in position 1 a circuit is closed from battery through the Winding oi relay 654-, back contact relay 655, back contact of relay 656, right contact of earn 657, and thence over conductor 1157 through the cross-connecting blocks to brush 1106 and to ground as previously traced. The operationojt relay 65 1: closes a circuit from ground over its left front contact throitigh resistance 7 -1 and lamp 705 to bat-- tery. Lamp 705 indicates that the district selector is being tested for busy condition and remains lighted until the district selector is ready i01 use as a. test selector. It also clos a circuit from ground through the winding; of relay 658, over the inner right -trout contactof relay 65 1, right contact of earn 650, conductor 660, lower left contact of care 101, Winding oil sequence switch mag net 100 to battery advancing sequence switch 100 to position 3. 'lhe operation of relay 65S closes a circuit from ground over its trout contact, left contact of cam 661, conductor 662, to the link circuit. This ground causes the link circuit to advance to find a sender and then. to put the district selector circuit through a simulated Wipe out call Without movi g the selector off-normal.

Relay connected through cam 671 to the automatic test set for district selectors rict selector which i in sucn a me. nor as to be operated it the district test set is testing the district selector to be used as a connecting selector. The oplamp 705 and the above operations until the test of the l...-1cllC-li has l 1.83.1 completed. I

When sequence switch 100 reaches position 1 following this Wipe out call or following a service call, a circuit will be closed from ground through the windings o1"- relay 663, winding of relay 664E, outer right front contact of relay 654i. lower left contact of cam 665, conductor 666, contact 103 of jack 104, lower contact of cam 105, resistance 106 to battery. If no link circuit is testing the district at this time, relay 663 Will operate and close a shunt. around its hi gh resistance Wi11ding, from ground at its front contact, over the lower contacts of cam 706, to its right Winding. Relay 6641, which is marginal, now operates and closes a circuit from battery, through the left Winding of relay 667' to ground at the front Contact of relay 661. Relay 667 in operating disconnects conductor 666 from the link circuit, and connects ground through resistance 668 over the upper contact oi: cam 669 to conductor 67 0, preventing the link circuits from taking this selector for use in a service connection.

The operation of relay 66d when sequence switch 100 reaches position 1, following a service connection, prevents the establishment of the above traced circuit for relay 658 nd the advance of the district selector se quence switch from position 1.

In addition, the operation of relay 667 closes a circuit from battery through the winding of relay 656, innermost right front contact of relay 667, lower contacts of cam 651, left front contact of relay 701 to ground at contact 61?.) of key 601. Relay 656 in operating opens the circuit of relay 65 1 and that relay release-s extinguishing lamp 7 05. Relay 656 also closes a holding ground for relay 667 which may be traced over the front contact 01 relay 656, right contact of earn 657, conductor 1157, through the cross-connecting racks associated With brush 1106 in its firstofl-normal position, conductor 709, lower contacts of cam 703, conductor 1, outer left front contact of relay 551, to ground at the back contactot relay 552. The release of relay 1 disconnects relays 663 and 664 from conductor 666. The operation of relay 667previously described also e2:- tends its operating ground over its left front contact, upper right and lower. left contacts or" cam 707, conductor 1158, front contact of relay 115 1, conductor 607, to the right Winding of relay 606 and battery. Relay 606 operates in this circuit and closes a circuit from battery through the sequence switch magnet 700, lower left. contact of earn 710, outer right front contact of relay sequeice switch 700 to position i is com- 6 pleied.

l i itll seeiience cii'cui l 01 to ground in much PGqUGDCG switch 500 advances to position 2.

606, contact 608 01? start :e*

lVlicii sequence switcli TOO leaves position 1 She operating circuit relay (306 is opened and that i-elziy releases, advancing 'ih sec eiice swilicli 700 to position 3 ii cirower h the winding of the magnet cc elf rel?" am 710, oiiler Ti 12 :17 (506 ground oi or (308 of start i: y

lie s i 3 lower right cents" ft contact of c2111 658, wind-- queiice switch lim e'c 650 o the connector switch ii the winding;

coniucii oi i'elziy T11 lower coiitiit v JOllllillli'il loi- :t'i'ip of Cibill 110 "to LL L i iisli Oil ex'lieiic conductors circuit to release.

it was contact '22, con- "sri'iing 'Ilml' R02 is cross-con- I circuit iiii zy 11.60, i- ,2 conductor $17 iO'V ($01. Llie confie Y 66? serves to hold use minel of biusli i' l iili sequence closccl [00 in posit" conductor I operates to ground. fiel' circuit 7 'itcli m2. 'V-jl'. iron; co

from coiiiizic" o' and lower right conic incl. Sequence swiiicli cation 4: in this circuit.

1 act ol oiitzici o'l? V O 1 Win l llHIUSJQS 801 and wliic i are "his circuit.

Lliei iei'i'; becl relay Willi sequence switch '4"- oi? relay .2; 21nd relay 1 izecl. i i' illi relay 1154.- 0 above traced circuit :lo advancing" c a circuit is closec wincl'iig of (list; conductor 676 l owe right contact of can: 

